The goal of this study is to develop low-dose radiation (LDR) as a new tool to prevent and treat diabetic nephropathy. Currently no effective preventive or therapeutic approaches are available to treat diabetic nephropathy, which is the most common cause of renal failure. We have been investigating the biological effects of LDR, including its hormesis and adaptive response, in vitro and in vivo. A major advantage of LDR is that it activates many genes in antioxidant and anti-inflammatory pathways, rather than just single protective gene, potentially making LDR a very potent and novel therapeutic approach. This was borne out by our preliminary studies that show that LDR at 25 mGy decreases diabetic nephropathy, by significantly reducing diabetes-induced renal oxidative damage and inflammation. Our latest preliminary data show up-regulation of nuclear factor erythroid 2-related factor 2 (Nrf2) expression and protein kinase B (also called Akt) phosphorylation in the kidney of diabetic mice, also exposed to LDR at 25 mGy. NRF2 is a transcription factor involved in expression of a broad range of protective genes. Therefore our central hypothesis is that exposure of diabetic animals to LDR can prevent and treat diabetic nephropathy by activation of many protective genes through stimulation of the Nrf2 pathway. This hypothesis will be tested through three specific Aims: (1) LDR at the optimal condition not only prevents, but also delay diabetic nephropathy; (2) the optimal LDR is safe for diabetic subjects; (3) the renal protection by the optimal LDR is predominantly mediated by up- regulating Nrf2-mediated multiple antioxidant components. The great advantage of LDR is that it offers a highly controllable, non-invasive method for eliciting endogenous, synergistic tissue protection and repair mechanisms. This innovative approach will be particularly valuable for the diabetic patient who already has significantly decreased renal function that increases the toxicity of invasive drugs. Therefore, this project will open a new avenue for the prevention and treatment of diabetic complications.